funny problem in C program !

[Suri]

hi im trying to run this simple program. any help shall be appreciated
..pls see error message.

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
int main()
{
double pic;
pic= 4.0 * atan(1.0);
printf("pi is = %f \n",pic);
}
error when i try to compile ...

[harshit@localhost ~]$ gcc harshit.c
/tmp/ccRf4QzM.o(.text+0x1b): In function `main':
: undefined reference to `atan'
collect2: ld returned 1 exit status

 

[Morris Dovey]

hi im trying to run this simple program. any help shall be appreciated
..pls see error message.

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
int main()
{
double pic;
pic= 4.0 * atan(1.0);
printf("pi is = %f \n",pic);
}
error when i try to compile ...

[harshit@localhost ~]$ gcc harshit.c
/tmp/ccRf4QzM.o(.text+0x1b): In function `main':
: undefined reference to `atan'
collect2: ld returned 1 exit status

^^^^^^^^^^^^^^^^^^^^^^^^^

Suri...

Not a compile problem. ld can't resolve atan() - try:

gcc -lm harshit.c

so that ld will know to search the math library.

--> See FAQ: http://www.eskimo.com/~scs/C-faq/q14.3.html

 

[Ben Pfaff]

Subject: funny problem in C program !

Yeah, it's so funny there's a FAQ for it. Please read the FAQ.

 

[Bruno Desthuilliers]

hi im trying to run this simple program. any help shall be appreciated
.pls see error message.

I can see 2 C-related problems :

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
int main()

should be int main(void) or int main(int argc, char **argv)

{
double pic;
pic= 4.0 * atan(1.0);
printf("pi is = %f \n",pic);

main must return an int. Default is EXIT_SUCCESS (defined in stdlib.h).

}
error when i try to compile ...

The compiler should at least warn you that it reaches the end of a
non-void function. If it doesn't, RTM and learn how to raise warning level.

[harshit@localhost ~]$ gcc harshit.c
/tmp/ccRf4QzM.o(.text+0x1b): In function `main':
: undefined reference to `atan'
collect2: ld returned 1 exit status

This is not a problem with the C language, it's a problem with your
linker. And it's a FAQ. RTF !-)

Bruno